Fig 8. Effect of Campylobacter jejuni challenge on the proliferation of cecal tonsil MNCs stimulated ex vivo.

On d14 of age, birds were weight-matched and randomly assigned to two treatments: control and challenge. Birds were orally challenged with 0.5 mL of 2.4 x 10⁸ CFU/mL of Campylobacter jejuni or mock-challenged with 0.5 mL of 0.85% saline. Cecal tonsil MNCs (5 x 10⁴ cells) were stimulated with 15 μg/mL of Con A or 20 μg/mL of lysed C. jejuni (CJ) on (a) d15 and d17 or Con A (15 μg/mL), CJ (20 μg/mL), 1:10 CJ (2 μg/mL), Salmonella Enteritidis (SE) OMP (20 μg/mL), or 1:10 SE OMP (2 μg/mL) at (b) 7 dpi, (c) 14 dpi, and (d) 21 dpi. The proliferation of MNCs was measured by MTT assay after 72 h of stimulation. Results were expressed as mean + SEM OD 570 values. *P < 0.05; **P < 0.01 compared with control (n = 6), Student’s t-test.